Matrix and retainer therefor

ABSTRACT

A matrix the end portions of which are provided with a common surface upon which are mounted a plurality in the longitudinal ribs. A retainer for use in the engagement of the ribs of the above matrix after the latter is placed in the desired position around the peripheral area of a tooth.

United States Patent [-191 Franklin et al.

[ 51 Dec. 17, 1974 MATRIX AND RETAINER THEREFOR Inventors: Mark E. Franklin, 29 Kaster Dr.,

Freehold, NJ. 07728; James R. Schmidt, 33 Birmingham Dr., Englishtown, NJ. 07726 Filed: Jan. 11, 1973 Appl. No.: 322,721

U.S. c1. 32/63 Int. Cl. A61 5/12 Field of Search 32/63; 128/325, 326,327,

References Cited UNITED STATES PATENTS Mattern 32/63 3,247,852 4/1966 Schneider 128/325 UX Primary Examiner-Robert Peshock Assistant Examiner.l. Q. Lever Attorney, Agent, or FirmEdward F. Costigan, Esq.

57 ABSTRACT A matrix the end portions of which are provided with a common surface upon which are mounted a plurality in the longitudinal ribs.

A retainer for use in the engagement of the ribs of the above matrix after the latter is placed in the desired position around the peripheral area of a tooth.

2 Claims, 7 Drawing Figures PATENTEIJ 3,854,210

SHEET 10F 2 PATENTEU SEC] 71974 1 MATRIX AND RETAINER THEREFOR This invention relates to a device for use in providing a positive base, support, shape, and contour for the receipt of material utilized in the restoration of the surface of a tooth.

More particularly, this invention relates to an improved matrix and an improved retainer therefor.

In general, a matrix is a band which fits around a tooth in a circumferential fashion and is used when a cavity on the side of the tooth is being filled or the outside of a tooth is otherwise being restored. The purpose of such a band is to confine the material utilized to restore such tooth to a specific site on the surface that is being restored and, also, to permit the restoration of the tooth to be made properly. A retainer is a device designed to secure and hold the matrix in the position desired.

In the art, there are a number of matrices and retainers utilized for the purposes heretofore described. In general, however, a number of such retainers are limited in use to a specific area of the mouth. For instance, some are designed for use on the anterior teeth, but may not be used on the posterior teeth and visa-versa. Also, a number of the retainers of the art have been found to be excessively loose after prolonged use on a number of patients for an extended period of time. The latter condition ultimately results in an improper pattern of size and shape for the proper restoration of teeth.

What is needed in the art is a combination matrix and complementary simple and inexpensive retainer therefor, the latter being of a size, shape and structure which is amenable to multiple banding within the same localized area of the oral cavity by a plurality of such combinations. The latter individual combinations should also provide the proper orientation relative to the individual tooth it is adapted for use on with respect to size, shape and contour for the achievement of the optimum in effective restoration of such tooth in a simple and efficient manner. The combination should also provide a sure and positive cinch of the band around the tooth, and easy load of the restoratory material accompanied by a quick disconnect without discomfort to the patient. Of course, this latter function of the retainer and matrix should only be accomplished after the material utilized in restoration has cured to a substantially hardened state.

The subject invention answers all of the aforesaid needs of the art with special emphasis on a combination matrix and retainer therefor which may be used in close proximity to another identical combination when both are fitted in either the anterior or posterior area of mouth.

It is an object of this invention to provide a combination matrix and retainer therefor, each of such combinations producing, within each other, a unique structural environment for improvement in the proper restoration of teeth in an effective and efficient manner.

Other objects and many of the attendant advantages of this invention will become more evident to one skilled in the art from a study of the following detailed specification taken with the accompanying drawings, wherein:

FIG. 1 is a view of the improved matrix band of this invention.

FIG. 2 is a view taken on line 22 of FIG. 1.

FIG. 3 is a view of the improved retainer of this invention in the open or receptive position for the matrix of FIG. 1.

FIG. 4 is a view of the retainer of FIG. 3 in the closed position without engagement of the matrix band.

FIG. 5 is a view taken on line 55 of FIG. 7 with section cut away showing the engagement of the matrix of FIG. 1 by the retainer of FIG. 4.

FIG. 6 is a cross-sectional view taken on line 66 of FIG. 4 showing the curvilinear shape of the inner side of the retainer without engagement of a complementary matrix.

FIG. 7 is an assembly view in section showing the engagement of the matrix by the retainer of this invention.

Similar numerals refer to similar parts throughout the several views.

In practise, the longitudinal body of the matrix is fitted circumferentially around the periphery of the tooth (not shown). The end portions 10 of such a matrix are brought into surface to surface contact, with the exterior surface of each of such end portion being provided with a plurality of ribs 1 1, the latter ribs projecting outwardly for engagement by the retainer 12 which will be hereinafter described.

As shown in FIG. 1, each of the ribs 11 are vertically oriented relative to the longitudinal body of the matrix.

FIG. 2 indicates that such rib 11 projects outwardly from the surface of the end-portion 10 of the matrix.

Referring now to FIG. 3, a flexible retainer 12 is shown in the open position which is adapted for receipt of the matrix 10. The body of the retainer 12, in the open position, is of the flexible U-shaped variety having a base 13 and two upwardly standing arms 14 and 15. The arm 14 terminates in an outwardly extending flange 16 and, as shown in this view, the upwardly extending arm 15 terminates in the shape of inwardly extending inner hook 17. The function of the latter hook 17 is to engage the flange 16 on the terminal portion of arm 14. In practise, the hook 17 may be of the concave variety adapted for separable mating engagement by the convex shape of the outer surface of the flange 16.

The inner surface of the arms of the retainer are provided with a triangular projection 21. However, the projection may be of a variety of shapes, as long as they function together to form a passage, the surfaces of which will engage the projecting ribs 11 of the matrix when the hook 17 engages the flange 16. It is to be noted that the above mentioned passage is fomied between the adjacent surfaces of both projections formed on the inner surface of both the arms of the retainer.

. When the sides or arms 14 and 15 of the flexible retainer are pressed inwardly, the mouth of the book 17 is then engaged to the outwardly extending flange l6, and the retainer will take on the substantially triangular shape shown in FIG. 4. Note the passage 19 formed between the projections 21 for the passage and subsequent fixation of the end portions 10 of the matrix. The latter fixation is more clearly shown in FIG. 5.

Referring again to FIG. 5, take note of the curvilinear surface 22 of the retainer in the area which is designed to be adjacent the surface of the tooth (not shown). Also, note the circular area 23 formed by the body 24 of the longitudinal matrix 11. This area 23 is adapted to circumferentially encircle the tooth which is to be restored. The end portions of the matrix, as heretofore stated, are each provided with a plurality of outwardly projecting ribs 11. The latter are engaged by the projections 21 and the body of the band is secured in position around the periphery of the tooth.

In summary, the longitudinal band or matrix is fitted around the periphery of a tooth. The end portions thereof shown in FIG. 1 are brought together and slipped into the retainer 12 while it is in the open position, shown in FIG. 3. A slight outwardly drawing action on the end portions of the matrix will insure a snug fit of the body of the matrix around the periphery of the tooth. The arms of the retainer are pressed inwardly and the retainer takes on the shape shown in FIGS. 4 and 5. As shown, the projections 11 are engaged by the teeth 21 of the retainer and a solid positioning of the body and end portions of the matrix in the desired posi tion are assured.

After the combination matrix and retainer have performed their function, the hook 17 may be manually disengaged from convex flange 16 and all elements may be easily removed from the tooth.

In conclusion, due to the unique structure and function of both the matrix and retainer of this invention, none of the problems of the prior art, as heretofore recited, are encountered. And, this is accomplished with the added ability to utilize the aforesaid elements in proximity with a similar combination in either the anterior and posterior area of the mouth. in closing, the device of this invention, which is a combination of both a matrix and retainer, is simple, inexpensive and easy to manipulate in the oral cavity to perform its function.

What is claimed is:

1. The combination of a matrix and retainer adapted for use in the precedure of restoring a tooth, said com bination consisting of:

a matrix comprising an elongated body including a tooth engaging portion and two end portions, said end portions adapted to be held together in longitudinal mating relationsjip, each of said end portions including a plurality of outwardly projecting ribs, and

a retainer removably secured to the end portions of the matrix, said retainer comprising an essentially triangular shaped body including a base and first and second upstanding arms, said first arm having a hook projecting inwardly toward the center of the retainer and said second arm having an outwardly projecting flange retained within said hook portion to removably hold the upper ends of the arms together, said retainer further including locking means in the form of projections located on the inside of each of said arms, said locking means gripping said matrix between said ribs whereby relative movement between the retainer and the matrix is prevented.

2. The combination of claim 1, wherein said hook may be manually disengaged from said flange in a facile manner thereby releasing said matrix band. 

1. The combination of a matrix and retainer adapted for use in the precedure of restoring a tooth, said combination consisting of: a matrix comprising an elongated body including a tooth engaging portion and two end portions, said end portions adapted to be held together in longitudinal mating relationsjip, each of said end portions including a plurality of outwardly projecting ribs, and a retainer removably secured to the end portions of the matrix, said retainer comprising an essentially triangular shaped body including a base and first and second upstanding arms, said first arm having a hook projecting inwardly toward the center of the retainer and said second arm having an outwardly projecting flange retained within said hook portion to removably hold the upper ends of the arms together, said retainer further including locking means in the form of projections located on the inside of each of said arms, said locking means gripping said matrix between said ribs whereby relative movement between the retainer and the matrix is prevented.
 2. The combination of claim 1, wherein said hook may be manually disengaged from said flange in a facile manner thereby releasing said matrix band. 